Biologist worked on controversial cloning that captured public imagination in mid-90s but outraged animal rights campaigners.
Keith Campbell, a prominent biologist who worked on cloning Dolly the sheep, has died aged 58, the University of Nottingham said.
Campbell, who had worked on animal improvement and cloning at the university since 1999, died on 5 October, a spokesman, Tim Utton, said on Thursday. He did not specify the cause of death, saying only that Campbell had worked at the university until his death.
Campbell began researching animal cloning at the Roslin Institute near Edinburgh in 1991. The experiments led to the birth in 1996 of Dolly the sheep, the first mammal to be cloned from an adult cell.
The sheep was named after the singer Dolly Parton. Researchers at the time said the sheep was created from a mammary gland cell, and that the voluptuous Parton offered an excellent example.
The creation of the sheep captured the public imagination and instantly became a scientific sensation. The experiments drew admiration but also anger from some who raised questions about the ethics of cloning.
Animal rights activists were outraged, while the Church of England expressed reservations. Dolly was put down in 2003 after she developed lung disease.
Campbell's interest in cellular growth dated back to his college days studying microbiology in London. "At this time it was known that the majority of cells within an adult contain an intact genome; however, many scientists were sceptical that the nuclei of such cells could be reprogrammed to control development. Stubbornly, I always believed that such technology was possible," he wrote in an autobiographical essay in 2008, when he was awarded the Shaw prize for medicine and life sciences.
He received the recognition along with Ian Wilmut, the lead scientist in the team that created Dolly, and the Nobel-winning scientist Shinya Yamanaka.
After the birth of Dolly, Campbell oversaw the successful cloning of pigs and lambs. In 1999, he joined Nottingham University as professor of animal development, where he continued research into the cloning process. He was particularly interested in assisted reproduction in both animals and humans, and studied ways to develop reproductive technologies in farm animals to enhance breeding and maintain food security.
He believed research into medical use of embryonic stem cells would eventually lead to important breakthroughs despite opposition from some who found the technique abhorrent.
"There are groups that believe that life begins at conception and that you should not do any research involving embryos at all," he said in a 2001 interview. "But we have also been able to inform people of the potential benefits, and once they learn about it they are much more likely to be in favour of it."
Campbell said stem cells from embryos had the unique ability to be developed into many different types of human cells, including blood, muscle and nerve cells.
"Broadly, I would say they may be a major breakthrough in human medicine that will improve the quality of life for a large number of the population, particularly those with age-related disorders," he said.
Campbell is survived by two daughters, Claire and Lauren.